1. Field of the Invention
The present disclosure relates to the technical field of display, more particularly, relates to an array substrate, a method for repairing the array substrate and a display apparatus.
2. Description of the Related Art
A TFT-LCD (Thin Film Transistor Liquid Crystal Display), as a panel display apparatus, is applied in a high performance display field more and more as it has characteristics, such as small volume, low power consumption, non-radiation and low manufacturing cost. The TFT-LCD is composed of an array substrate and a color filter substrate. Liquid crystal is filled between the array substrate and the color filter substrate. By controlling the deflection of liquid crystal, light intensity may be controlled and then an image is displayed by the color filter substrate.
The conventional process of producing the TFT-LCD mainly includes four stages, i.e., a process of producing the color filter, an Array process (array substrate manufacturing), a Cell process and a Module (assembly) process. A Cell Test process may be further provided between the Cell process and the Module process. In the Cell Test process, it is found that, when impurities such as dusts, organics, metal are adsorbed to regions in the display panel close to the color filter, sub-pixels corresponding to these regions often transmit the light with a luminance much greater than that of other normal sub-pixels, i.e., generating a phenomenon of bright pixel defect. For example, taking a normally white picture display mode of a liquid crystal panel as an example, pixels in such liquid crystal panel are displayed as white color without being energized electrically while the pixels are normally displayed as black color with being energized electrically. If a pixel energized electrically is displayed as white color instead of black color, the pixel will be called as a bright pixel. Such bright pixel which cannot be controlled may cause light leak of the display panel and may degrade the quality of the display panel seriously, and thus it needs to repair the sub-pixels with the bright pixel defect.
With reference to a display panel in prior art, as illustrated in FIG. 1, it comprises a gate line 11 and a data line 12 crossing with each other; a thin film transistor (TFT) arranged at the crossing positions of the gate line 11 and the data line 12; a common electrode line 13 parallel to the gate line 11; and a pixel electrode 14 connected to a drain electrode of the TFT. In order to repair the bright pixel defect in display panel, generally, the pixel with the bright pixel defect is darkened by a laser welding, in particular, the pixel electrode 14 with the bright pixel defect is provided with a repairing point 15 and the laser welding is performed at the repairing point 15. By the laser, ITO for forming the pixel electrode 14 is melt and is electrically conducted to the gate metal layer for forming the gate electrode of the TFT. At that time, the driving voltage for the pixel with the bright pixel defect varies as the voltage of the signal varies, and the liquid crystal molecules of the pixel are always in deflection state to present the effect of a dark pixel.
In the conventional repairing process, in order to reduce the coupling effect of parasitic capacitance between the pixel electrode 14 and the gate line 11 to avoid the degradation of the display effect (the jumping of the gate voltage may cause charge redistribution inside the pixel thereby causing variation of the pixel voltage), it is necessary to set the size of the repairing point as small as possible to reduce the coupling effect of parasitic capacitance.